JOHANNESBURG  Nelson Mandela remains hospitalized in South Africa for an eleventh day after undergoing surgery and receiving treatment for a lung infection.

South Africa’s government has said the 94-year-old Mandela was admitted Dec. 8 to a hospital in the country’s capital, Pretoria.

Officials said Mandela underwent an endoscopic surgery to remove gallstones Saturday after doctors treated him for a recurrent lung infection.

Presidential spokesman Mac Maharaj, who has issued statements previously about Mandela’s health, did not respond to requests for comment Tuesday.

Mandela is revered for being a leader of the struggle against white rule in South Africa, serving 27 years in prison for his beliefs. He served one five-year term as president before retiring from public life.